Crystal structure and refinement of cytochrome P450terp at 2.3 A resolution.
J Mol Biol
; 236(4): 1169-85, 1994 Mar 04.
Article
en En
| MEDLINE
| ID: mdl-8120894
ABSTRACT
Cytochrome P450terp is a class I (mitochondrial/bacterial) P450 that catalyzes the hydroxylation of alpha-terpineol as part of the catabolic assimilation of this compound by a pseudomonad species. Crystals grown from the purified protein have the symmetry of space group P6(1)22, and cell dimensions a = b = 69.4 A, c = 456.6 A, alpha = beta = 90 degrees, gamma = 120 degrees. Diffraction data were collected at the Cornell High Energy Synchrotron Source, and the structure of P450terp was solved by a combination of molecular replacement and multiple isomorphous replacement techniques. A model of P450terp was built and refined against native data, to an R-factor of 18.9% for data with I > or = sigma(I) between 6.0 A and 2.3 A resolution. This model contains 412 of the 428 P450terp amino acid residues; the loop between helices F and G is disordered in the crystal. While the overall fold of P450terp is very similar to that of P450cam, only three-quarters of the C alpha positions can be superimposed, to a root-mean-square deviation of only 1.87 A. The mode of substrate binding by P450terp can be predicted, and probable substrate contact residues identified. The heme environment and side-chain positions in the adjacent I-helix suggest possible modes of proton delivery in the catalytic cycle of the enzyme.
Buscar en Google
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Sistema Enzimático del Citocromo P-450
/
Oxigenasas de Función Mixta
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
J Mol Biol
Año:
1994
Tipo del documento:
Article